DE1921946A1 - Process for the preparation of aqueous dispersions of polymers of olefinically unsaturated monomers - Google Patents

Description

Badische Anilin- & Soda-Fabrik AG 1921 946

Our reference: 0.Z. 26 I65 wd / bm 6700 Ludwigshafen, April 29, 1969

Process for the preparation of aqueous dispersions of polymers olefinically unsaturated monomers

Polymer dispersions produced by emulsion polymerization are usually extremely fine and their particle size distribution is relatively narrow. For some areas of application however, coarse-particle dispersions are advantageous. It is known that finely divided dispersions are already relatively small Solids contents so viscous that they are difficult to handle are. Concentration to higher solids levels is common only possible with great effort or in some cases not at all. In contrast, there are coarse-particle dispersions low viscosity, easy to concentrate and still flowable even with high solids contents.

Attempts have already been made to produce coarse-particle dispersions by that emulsifier was metered in during the polymerization. In many cases, however, considerable amounts of coagulate are formed. In addition, it is often necessary to extend the duration of the polymerisation be accepted.

Emulsion polymerization in the presence of protective colloids such as polyvinyl alcohol or hydroxyethyl cellulose leads to the formation of coarse dispersions, especially in the case of vinyl esters (cf. German Patent 1,029,565 ), but such protective colloids increase the viscosity undesirably. It is also known from DAS 1 223 160 that coarse synthetic rubber latexes can be produced by adding aqueous solutions of an alkali polyacrylate as an agglomerating agent during the emulsion polymerization. In this process, however, aqueous butadiene polymer dispersions are obtained which give films with a relatively high water absorption capacity.

Finally, it is still, for example from US Patent ^515/68 009845/1774 ^{r 2} "

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2 993 020, known, by the so-called process of freeze agglomeration to produce coarse-particle dispersions from finely divided aqueous synthetic rubber dispersions however, in general, a relatively large amount of effort is required and the process cannot be based on polymer dispersions, which are produced with any emulsifiers and have any pH values are generally used. Often form considerable amounts of coagulate in the process of freeze agglomeration.

It has now been found that aqueous dispersions of polymers of olefinically unsaturated monomers (A) can be prepared with advantage by polymerizing the monomers (A) in aqueous emulsion in the presence of customary dispersing aids, catalysts and prefabricated emulsion polymers of olefinically unsaturated monomers if, based on the Monomers (A) O ₅ I to 30 percent by weight of the prefabricated emulsion polymers, which contain 0.5 to 50 $> their weight of olefinically unsaturated monomers (B), which give polymerized water-soluble homopolymers, polymerized in, in worm an aqueous dispersion during the polymerization of the monomers (A) up to a conversion of these monomers of 95 % , the proportion of monomers (B) in the monomers (A) by at least 20 percent by weight, based on the amount of monomers polymerized into the prefabricated emulsion polymer ( B) should be smaller »According to the new method, one obtains w Aqueous polymer dispersions, in which the dispersed polymer particles are much larger than they would be if the composition were the same, were carried out in a conventional manner.

In the new process, the usual olefinically unsaturated Monomers in the customary monomer ratios alone or in a mixture using those customary for their polymerization Emulsifying and dispersing auxiliaries and catalysts in the case of the emulsion polymerization for these monomers; Dispersing aid and catalysts, customary temperature and, if necessary, pressure conditions have to be polymerized «, of course in the process, the prefabricated polymer dispersions added in d © n contained dispersing agents with the

009845/17 74 '_ ₃ _

dispersants used in the new emulsion polymerization and other auxiliaries, such as catalysts, be compatible. In addition, the prefabricated emulsion polymers a larger proportion of olefinically unsaturated monomers (B), which polymerize by themselves, give water-soluble homopolymers, Contained in copolymerized form than the emulsion polymers prepared by the new process.

As olefinically unsaturated monomers (A). from which to the new Process coarse polymer dispersions can be produced, for example monoolefinically unsaturated carboxylic acid esters with 4 to 20 carbon atoms, such as vinyl esters of saturated 2 to 12 carbon atoms containing monocarboxylic acids, such as vinyl acetate, vinylpro-

Vinyl laurate}

Plonate, vinyl n-butyrate / vinyl stearate and vinyl esters of so-called vesatic acids, esters of _t <, ß -olefinically unsaturated, preferably 3 to 5 carbon atoms containing mono- and dicarboxylic acids and straight-chain ones containing up to 18 carbon atoms branched or cyclic alkanols, such as especially the methyl, ethyl, n-butyl, tert-butyl, cyclohexyl, 2-ethylhexyl, lauryl or stearyl esters of acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid and / or Itaconic acid, νiny! Aromatic monomers, such as styrene, «: -MethyIstyrene, vinyltoluenes, vinylxylenes, vinylethylbenzenes and chlorostyrenes, nitriles ot, ß-olefinically unsaturated carboxylic acids, such as acrylic and / or methacrylonitrile * ·, vinyl and / or vinylidene halides, such as especially vinyl chloride and vinylidene chloride, and I, j5-dienes, such as butadiene and isoprene in particular.

The monomers (A) used are up to about 15, usually only up to 10 percent by weight, based on the total monomers (A) as well monoolefinically unsaturated monomers with reactive groups such as OC ^ ß-olefinically unsaturated, preferably containing 3 to 5 carbon atoms Mono- and / or dicarboxylic acids and / or their optionally substituted amides, such as especially acrylic acid, methacrylic acid, Crotonic acid, maleic acid, itaconic acid, acrylamide, methacrylamide, maleimide, maleic anhydride, maleic acid diamide, crotonic acid amide, Itaconic acid diamide, N-methylol-acrylamide, N-methylol methacrylamide, N-Methoxymethyl- and / or -methacrylamid, N-Äthoxymethyl-acryl » and / or methacrylamide and / or N-n-butoxy

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oz _2616J ^19219A6

methyl acrylic and / or methyl acrylamide, N-n-butyl methacrylamide, N-acetoxymethyl acrylic and / or methacrylamide, vinyl sulfonic acid, Vinylphosphonic acid and its salts, heterocyclic vinyl compounds, such as vinylpyrrolidone, N-vinylimidazolium salts, vinylpyridines, Vinylcaprolactam and N-vinylcarbazole are possible. The amount such monomers is usually in the range from 0.1 to 10, in particular from 0.5 to 6 percent by weight.

The emulsifiers used in the new process in the usual amounts, ie generally in amounts of 0.5 to 5 percent by weight, based on the amount of monomers (A), are the monomers to be polymerized in each case in an aqueous emulsion ( A) or mixtures of monomers (A), customary emulsifiers in question, as described in detail in the book by Houben-Weyl "Methods of Organic Chemistry", Volume XIV / l, "Macromolecular Materials" Georg-Thieme-Verlag, Stuttgart, 196I , Pages 192 to 208. Suitable anionic emulsifiers are, for example, lauryl sulfate, p-isooctylbenzenesulfonate, dodecylsulfonic acid, sulfuric acid half-esters of addition products of alkylene oxides, especially ethylene oxide, with alkylphenols, such as p-isooctylphenol in particular, these addition products usually bearing 10 to 50 ethylene oxide residues. Suitable anionic emulsifiers are also so-called soaps, such as alkali or ammonium salts of fatty acids, such as palmitic, oleic and stearic acid. Nonionic emulsifiers can also be used, for example products such as those produced by the addition of alkylene oxides, especially ethylene oxide, to fatty acids such as palmitic, oleic or stearic acid, fatty alcohols such as sperm oil alcohol, or fatty amines such as stearylamine or oleylamine, and fatty acid amides such as stearic acid amide or lauric acid amide are obtained , these addition products usually carrying 10 to 50 ethylene oxide units. In addition, customary protective colloids can also be used in small amounts in some cases.

The catalysts for the new process are water-soluble ones peroxidic compounds, such as hydrogen peroxide and alkali or » Ammonium persulfates, as well as oil-soluble radical-forming initiators, such as organic peroxides, for example benzoyl peroxide, p-menthane hydroperoxide and cumin hydroperoxide, and easily decomposable azo compounds of the azo-diiso-butyric acid nitrile type in Ereige.

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When using such "free-radical forming respectively, of peroxidic initiators usually carried out at temperatures of about 50 to 100, especially from 60 to 90 ⁰ C. Substituting conventional redox catalysts, for example mixtures of peroxidic catalysts of the type and reducing agents mentioned, such as hydrazine, soluble oxidizable Sulfoxylverbindungen , such as alkali salts of hydrosulphides, sulphoxylates, thiosulphates, sulphides and bisulphides and optionally traces of heavy metals for activation, it is also possible to work at lower temperatures, for example in the range from about 0 to 50 ^° C. The amount of catalysts used is in the usual range, ie generally between 0.005 and 2 percent by weight, based on the weight of the monomers (A).

In the new process, conventional regulators, such as long-chain ones, can also be used Alkyl mercaptans, unsaturated alcohols, such as sec. Butenol, or Xanthates, such as isopropyl xanthate, can also be used.

In the new process, prefabricated emulsion polymers are added to the polymerization mixture in the form of an aqueous dispersion during the polymerization. The amount of prefabricated emulsion polymers is 0.1 to 30, preferably 0.1 to 10 parts by weight per 100 parts by weight of the monomers (A). The prefabricated emulsion polymers should be added up to a point in time at which up to 95 % of the total of the monomers (A) to be polymerized have polymerized. It can take place immediately after the start of the polymerization, ie practically as soon as a polymerization can be recognized, for example by the onset of turbidity. If the prefabricated emulsion polymers are added to the polymerization batch before the beginning of the polymerization of the monomers (A), coagulation of the polymer which later forms generally takes place. The prefabricated emulsion polymer content of the aqueous dispersion to be added can be varied within wide limits. The dispersions generally contain (before their addition to the polymerization mixture) 5 to 60, preferably 10 to 50 percent by weight of emulsion polymer, based on the prepared aqueous dispersion,

The ready-made aqueous dispersions of emulsion polymers can in a conventional manner from olefinically unsaturated

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th monomers of the type mentioned above using the usual dispersing agents and catalysts under the usual temperature and pressure conditions. The prefabricated emulsion polymers should generally contain less than 20% 1,3 * - dienes of the above-mentioned type polymerized / since larger proportions of polymerized 1,3-dienes can be particularly problematic if the prefabricated emulsion polymers are added to the new process adds a point at which the majority of the monomers (A) has not yet polymerized. However, small amounts of 1,3-dienes in the prefabricated emulsion polymers are generally not a problem.

The prefabricated emulsion polymers should contain 0.5 to 50, preferably 2 to 15 % of their weight of monomers (B) in copolymerized form. Suitable monomers (B), when polymerized results in ₅ water-soluble homopolymers, for example, _"(are v, ß ~ olefinically unsaturated, preferably 3 to 5 carbon atoms containing mono- and / or dicarboxylic acids, such as acrylic acid ^, methacrylic acid, crotonic acid, maleic , Fumaric acid, itaconic acid, tetraconic acid and mesaconic acid or their alkali or ammonium salts, half esters of dicarboxylic acids of this type KBit alkanels, such as methyl, ethyl and isopropyl alcohol, and salts of such half esters, also optionally substituted amides of at, ß-olefinisc'h unsaturated Carboxylic acids of the type mentioned, such as acrylamide, methacrylamide, maleic acid diamide and / or monoamide, N-methylacrylamide, Nn-butyl methacrylamide, N-methylol-acrylamide and methacrylamide, ethers and esters of such N-hydroxyalkylcarboxamides, such as especially the methyl, ethyl , 3-oxabutyl, 3,6-dioxaheptyl and 3,6 ^ 9-trioxadecyl ethers and ethylene glycol monoethers or the acetic acid or propionic acid ester of N-methylol-acrylamide, N-methylol-methacrylamide and N-methylol-maleinimide, also ester amides of olefinically unsaturated dicarboxylic acids of the type mentioned of the kind mentioned with Glykoien and Polygly ^ clei '^. such as ethylene glycol, propylene glycol, 1,2- and 1,3-butylene glycol, 1,2- and 1,4-diethylene glycol, triethylene glycol and tetraethylene glycol, Mannich bases from acrylamide or 'methacrylamide, formaldehyde and dialkylamines with 1 to 12 carbon atoms in the Alkyl groups, vinylsulfonic acid

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ren, vinylphosphonic acid and styrene sulfonic acid and their alkali and ammonium salts and acrylic and methacrylic acid esters of hydroxyalkyl sulfonic acid, such as isethionic acid. The proportion of such monomers (B) in the prefabricated emulsion polymers should be 20 % greater than the proportion of such monomers in the monomers (A) if the new process is to produce copolymers which contain such monomers (B) in copolymerized form. The proportion of monomers (B) in the prefabricated emulsion polymers should only be high enough that the emulsion polymers are present as an aqueous dispersion, that is to say that the prefabricated emulsion polymers when added to the monomers polymerizing in emulsion (A ) are insoluble in the aqueous phase. Prefabricated emulsion polymers in which the proportion of monomers (B) is so large that they go into solution in an alkaline range, for example at pH 9, can therefore only be used in a neutral or acidic medium.

In addition to the monomers (B), the prefabricated emulsion polymers also contain other olefinically unsaturated monomers, such as monoolefinically unsaturated carboxylic acid esters, vinyl aromatic compounds, vinyl and / or vinylidene halides and / or nitriles οί, β-olefinically unsaturated carboxylic acids, and also optionally vinyl ethers, vinyl ketones and / or vinyl sulfonic acid ester polymerized into it. Olefinically unsaturated monomers of this type are given in detail above. Containing the pre-emulsion polymers acidic groups such as carboxyl groups or sulfonic acid groups _s, so they are particularly effective at pH values above. 7 In some cases it is advantageous that the prefabricated emulsion polymer is built up from the same monomers that are to be polymerized in emulsion by the new process.

In a special embodiment of the new method such ready-made aqueous dispersions of emulsion polymers used, in the preparation of which initially some of the monomers (B) together with other olefinically unsaturated mono-, mers of the above type copolymerized and then monomers (B) or a mixture of olefinically unsaturated monomers with a relatively high proportion of monomers (B)

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are grafted. Such prefabricated aqueous dispersions of emulsion copolymers are highly effective, even if they are only a relatively small amount of monomers (B) polymerized in total contain.

In a further embodiment, as aqueous dispersions prefabricated emulsion polymers used those whose polymer particles have hydrophilic groups only after their preparation, for example by saponifying polymerized esters or nitriles of unsaturated carboxylic acids with at least 3 carbon atoms or of polymerized vinyl esters, such as vinyl acetate in particular, have taken place. As such an aqueous dispersion of a ready-made Emulsion polymers are e.g. partially saponified polyvinyl acetate

"Highly effective dispersions, the acetate groups of which are partly saponified in an acidic or alkaline medium after the dispersion has been prepared. Partially saponified aqueous dispersions of vinyl acetate copolymers, which generally contain more than 30% vinyl acetate in polymerized form, are also suitable. polymers can be formally regarded as dispersions of such mixtures of olefinically unsaturated monomers, the monomers (B) vinyl alcohol copolymerized form. the pre-emulsion polymers contain 0.5 to 50, preferably 2 to 25% copolymerized their weight of monomers (B). In some cases, a content of such monomers of 0.5 to 3 percent by weight is sufficient, especially if they are grafted onto a backbone polymer as a mixture with other olefinically unsaturated monomers, even if the backbone polymer does not contain any monomers (B) in copolymerized form The composition of the prefabricated emulsion polymer can be varied within wide ranges with regard to the olefinically unsaturated monomers used, which polymerize on their own and result in water-insoluble homopolymers and, if appropriate, be adjusted to the composition of the polymer to be produced. For the preparation of aqueous dispersions with a predominant proportion of polymerized acrylic ester, for example, ready-made aqueous dispersions of copolymers containing 90 to 95 % of their weight of acrylic and / or methacrylic acid esters containing 1 to 4 carbon atoms, straight-chain or branched alkanols and 5 to 10 % of their weight in amides

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qC, β-olefinically unsaturated carboxylic acids, preferably containing from 5 to 5 carbon atoms, in polymerized form, particularly suitable. Ready-made aqueous dispersions of copolymers of 90 to 96 % of their weight of acrylic and / or methacrylic acid esters of straight-chain or branched alkenols containing 1 to 4 carbon atoms and 4 to 10 % of their weight of αL, β-olefinically unsaturated, preferably are also very suitable Mono- and dicarboxylic acids containing 3 to 5 carbon atoms. The effectiveness of these prefabricated dispersions with carboxyl groups mentioned can be increased if they have been used in emulsion polymerization systems with pH values above 7.

The prefabricated polymer dispersions can be added to the polymerization mixture at the beginning all at once or in batches or continuously during the polymerization up to a conversion of 95 % of the monomers (A). A conversion range of the monomers (B) between 20 and 95 % has proven particularly useful If they are fed in continuously or in batches as they are consumed, the prefabricated dispersion can be fed to the polymerization vessel as a mixture with an emulsion of the monomers (A) fed in or separately therefrom.

It is an advantage of the new method that there is a great deal of variation and suitable for the production of coarse dispersions from a large number of different monomers is. Another advantage of this new process is that coarse dispersions of such polymers are also produced according to it whose glass transition temperature is above room temperature. The coarse-particle polymer dispersions obtained by the new process are generally easy to store and above all suitable for the production of coatings, coverings and enrichments.

The following examples are used as a measure of the mean particle size so-called LD values (light transmission values) are given. The LD value indicates what percentage of white light through

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a 1 cm thick layer of a 0.01 percent polymer dispersion falls on a photocell, compared to the light transmission of a 1-centimeter-thick layer of distilled Water under all other conditions. The smaller the LT value, the larger the mean particle size of the polymer dispersion. The surface tension (OS) of aqueous dispersions can also vary with the same polymer composition and amount and type of dispersing aid and, if the method of production is the same, can be regarded as a measure of the mean particle size. Ever the greater the surface tension, the lower the mean one Partial diameter of the dispersion.

In the following examples, the parts and percentages relate to weight. For the monomers used who = the names are abbreviated as follows

B. = η-butyl acrylate As = Acrylic acid Bu =. Butadiene MAs = Methacrylic acid St. = Styrene MAM = Methacrylamide N = Acrylonitrile YAc = Vinyl acetate A. = Ethyl acrylate VPr = Vinyl propionate MM = Methacrylic acid

methyl ester

Example 1 to 14

400 parts of monomers (A) of the type given in Table 1 below are emulsified in a mixture of 40 parts of 20 percent strength aqueous lauryl sulfate solution and 2 parts of potassium persulfate in 560 parts of water. In each case 10 % of the monomer emulsion are heated to 80 ° C. and polymerized for 15 minutes with stirring. The remaining 90 % of the monomer emulsion are then added uniformly over the course of an hour, a total of 30 parts of a conventionally prefabricated 40 percent aqueous dispersion of a copolymer of 95 parts of ethyl acrylate and 5 parts of methacrylamide of a certain amount of the inflow of the remaining 9QQ parts of the monomer emulsion ^, given in the following table 1 in column 4, is either all at once (G; column 3 of table .1) or in a mixture with the

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remaining part of the monomer emulsion (Z; column 3 of the table l) admits. Thus, in Table 1, the combination "Z 50" means that after running in 450 parts of the monomer emulsion the remaining 450 parts of the monomer emulsion together with the 30 Parts of the 40 percent strength ethyl acrylate copolymer dispersion mentioned be dosed evenly. "G 25" means that the 30 parts of the 40 percent ethyl acrylate copolymer dispersion are added all at once after 225 parts of the monomer emulsion have flowed in, "G 0" means that after For 15 minutes, polymerizing the 100 parts of the monomer emulsion submitted to the 30 parts of the prefabricated EthyIacrylat copolymer dispersion added and then the remaining 900 parts of the monomer emulsion added uniformly over an hour be, "Z 0" means that after 15 minutes The remaining 100 parts of the monomer emulsion are polymerized 900 parts of the monomer emulsion mixed with the 30 parts of the prepared ethyl acrylate / flour polymer dispersion be closed evenly within an hour.

After all of the monomer emulsion has been added, the mixture is allowed to polymerize at 80 ° C. for a further 30 minutes. Receives after cooling one aqueous polymer dispersions, their LT value and surface tension (OS) in columns 5 and 6 of the following table 1 are given.

Table 1

Example no.

Monomers (A)

Type of addition (X) of the prepared dispersion

Data of the dispersions obtained

100 B WW - * -
from
the VfAiAVl UMXUUA IUVAi ^ W
Y % of the 900 parts
Monomer emulsion LD value
(JO OS
(dyn / cm) 100 B X Y 1 100 B Z 0 28 34 2 100 B Z 50 34 38 3 100 B Z 75 23 34 · 4th 100 B G 0 37 40 5 G 25th 29 38 6th G 50 24 35

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Example Monomers (A) No.

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Addition of type (X) (fee vö rge finished dispersion with a feed amount of Y% of the 900 parts of the monomer emulsion

Data of the dispersion obtained

LD value OS {%) (dyn / cm)

7th 100 B G 75 19th 34 8th 100 pc CSJ 0 10 Λ8 9 100 pc Z . 25th 13th 56 Io 100 pc Z 50 15th 57 11th 100 pc Z 75 14th 54 o 12th 97.2 St, 2.8 As G 0 33 38 13th 50 St, 50 B Z 0 · 27 39 i4 70- B, 30N Z 90 6th 30th

Example I5 to 19

400 parts of monomers (A) of the type given in Table 2 below are emulsified in a mixture of 40 parts of 20 percent aqueous lauryl sulfate solution and 2 parts of potassium persulfate in 56O parts of water and the pH is increased by adding aqueous potassium hydroxide solution 9.5 placed. Add 100 parts of the resulting monomer emulsion into the polymerization vessel, heated to 8O ⁰ C and polymerized for 15 minutes. The remaining 900 parts of the monomer emulsion are then added over the course of an hour by mixing the monomer emulsion with 30 parts of a conventionally prefabricated 40 percent aqueous dispersion of a copolymer after adding the proportion given in column 3 of Table 2 below from 95 parts of ethyl acrylate and 5 parts of acrylic acid can run in. After all of the monomer emulsion has been added, polymerization is allowed to take place at 80 ° C. for a further half an hour. Polymer dispersions are obtained which, after cooling, have the LT values and surface tensions (OS) given in Table 2 below.

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Table 2

Example: Monomer addition of the prefabricated construction data of the received No. (A) after a feed amount of dispersions

from ..'. % of 900 parts of LD values- 'OS monomer emulsion {%) (dyn / cm)

15th 100 B 0 16 100 B 25th 17th 100 B 50 18th 100 pc 0 19th 100 pc 50

18th 32 18th 33 30th 33 2 35 2 35

Example 20 to 32

400 parts of monomers (A) of the type given in Table 3 below are emulsified in a mixture of 2 parts of potassium persulfate in 560 parts of water which has the emulsifier content given in column 3 of Table 3 below. 100 parts of the monomer emulsion are heated in a polymerization vessel at 8O ⁰ C and polymerized for 15 minutes at this temperature. Unless otherwise stated, 30 parts of a conventionally prefabricated 40 percent aqueous dispersion of copolymers of the composition given in column 4 of Table 3 below are added to the remaining 900 parts of the monomer emulsion and the mixture is left uniformly within a Hour with stirring at a polymerization temperature of 8O ⁰ C run. After the addition, polymerization is carried out at 80 ° C. for a further half an hour. The LT values and surface tensions (OS) of the aqueous dispersions obtained are given in Table 3 below.

- 14 00 9 8 / * 5/17 TA

Ex.
No. ■■

Monomers (A)

Emulsifier
(based on the
Monomers A)

Copolymer of the prepared dispersion

Data of the dispersions obtained
LD value OS
{%) (dyn / cm)

St.

St.

St, 6, MAs
St, 10 MAs
St.
St.

St V
MM, 3 as

7C Bu, 30 St ⁿ

St, 39 Bu,
MAM

2 % Laury! Sulfate +++++) 50.5 A,

48.5 VAc, 1 vinyl alcohol

2 % lauryl sulfate +++++) 98.5 VAc,

1.5 vinyl alcohol

2 % lauryl sulfate
£ 2 lauryl sulfate
2 % potassium oleate

58 VPr, 28 M, 14 As 58 VPr, 28 M, 14 As 95 A, 5 MAM

1.5 % Na salt of a 95 A, 5 MAM

₅₇

acid mixture
1.5 % emulsifier a)

48.5 VAc, 1.0 vinyl alcohol

6th
21

2
15th

2 % Emulsifier b) 95 A, 5 MAM 48 2 .% Lauryl sulfate 75 A, 20 As, 5 Am 4th 2 Potassium oleate 95 A, 5 MAM 2 2 Lauryl sulfate +++++) 50.5 A,

37

37

-41

44

46 34 49 42

ro-αχ

Ex.
No. Monomers (A; Emulsifier
(based on the
Monomers A) ' Mixed polymer
the prefabricated
ten dispersion Data of the received
Dispersions
LD value OS
{%) (dyn / cm) 49 1
1— ■ 30th 54 St, 44 B,
2 MAM ++) 2 % lauryl sulfate 58 VPr, 28 M, 14 As 19th 37 UI
I. 31 100 VPr ⁺⁺⁺ ' 2 % emulsifier a )
3 % emulsifier c) 58 VPr, 28 M, 14 As 33; 37; 0091 32 60 B, ν
40 VAc ' 3 % emulsifier c)
'' i '. ■';.; 55.5 A, 33.5 MAS,
11.0 As 30th CjV ' Remarks;

+) Addition of the additional dispersion at 25 % feed

++) Only 10 parts of the 40 percent additional dispersion were used +++) Addition of the additional dispersion with an inflow of 95% ++++) Only 20 parts of the 10 percent additional dispersion were used

+++++) vinyl acetate polymer, partially saponified

Emulsifier
: a) Adduct of about 25 moles of ethylene oxide with p-isooctylphenol

b) triethanolamine salt of dodecylbenzenesulfonate (mixture of isomers)

c) Na salt of the acid sulfuric acid ester from a)

CD N)

CD cn

ΓΟ

-16- O.Z. 26 165 comparative tests 1 to 11

Monomers (A) are polymerized in an aqueous emulsion, as indicated in Examples 1 to 32, with the proviso that none prefabricated aqueous dispersions of polymers are added. Comparative experiments 1 to 11 were added to the in Column 2 of the following Table 4 carried out examples. In the following table 4 in columns 4 and 5 are the LD values and surface tensions (OS) of the aqueous polymer dispersions obtained in the comparative tests are listed,

for example Table 4 OS Compare Vers. No. LD value (dyn / cm) No. 1 to 7 and 46 1 15 to 17 78 8 to 11.18 64 2 12th , 19 72 57 3 22nd 81 58 4th 23 79 52 5 27 83 36 6th 28 91 69 7th 29 93 61 8th 30th 68 65 9 31 73 41 10 32 ■ 60 40 11th 76

A comparison of the LD values and surface tensions given in Table 4 with those in Tables 1 to 3 for those corresponding to the comparative experiments with regard to the monomer composition Examples (column 2 of Table 4) given LD values and surface tensions shows that in the new process Aqueous dispersions are obtained whose polymer particles are significantly larger than the polymer particles of aqueous Dispersions produced under comparable conditions in · conventional Way are made.

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Claims (1)

Claim Process for the preparation of aqueous dispersions of polymers of olefinically unsaturated monomers (A) by polymerizing the monomers (A) in aqueous emulsion in the presence of customary dispersing aids, catalysts and prefabricated emulsion polymers of olefinically unsaturated monomers, characterized in that, based on the monomers ( A.), 0.1 to 30 percent by weight of the prefabricated emulsion polymers, which contain 0.5 to 50% of their weight of olefinically unsaturated monomers (B), polymerized by themselves, result in water-soluble homopolymers, in polymerized form in an aqueous dispersion added during the polymerization of the monomers (A) up to a conversion of these monomers of 95 % , the proportion of monomers (B) in the monomers (A) by at least 20 percent by weight, based on the amount polymerized into the prefabricated emulsion polymer Monomers (B), should be smaller. Badische Anilin- & Soda-Fabrik AG Ad : 0 9 8 4 5/17 7 4